Dental needle



A. J. SON

DENTAL NEEDLE Aug. 18, 1959 Filed Nov. 17, 1955 2 Sheets-Sheet 1 Aug. 18, 1959 A. J. soN

DENTAL NEEDLE 2 Sheets-Sheet 2 Filed Nov. 17, 1955 ,.zeflbz) Zg WMU/1, MM@ 1- W Miami-g5 2,899,958 DENTAL NEEDLE Anthony J. Son, Mattapan, Mass. p Application November 17, 1955, Serial No. 547,416 4 Claims. (Cl. 1285215) This invention relates to subcutaneous injectioninstruments and more especially to those of the type commonly known as dental syringes. j

Reference is made to my previous United States patents, Number 2,484,657 for Dental Syringes and Number 2,545,115 for Dental Syringes, in which are disclosed improved constructions of dental syringes utilizing replaceable injection needles and a novel type of needle guard by which the exible injection needle may besupported and directed in angular relationship with respect to the body of the syringe so as to facilitate the introduction of the needle into the gum of the patient.

In order that the nature of the present invention may be more clearly understood, a brief description` of the procedures followed .by a dentist in the treatment of teeth under certain circumstances should be given. In the extraction of teeth or in the lling of certain types of cavities, 'it may be necessary to inject novocaine or other pain deadening drug into the gum adjacent to the tooth. For this purpose injection needles in the nature of that class of needles known as hypodermic needles have been devised, which are usually of substantial length and of considerable flexibility. The needle is customarily injected into the gum between the tooth and the gum so that when the novocaine is forced through the needle it will be in the immediate presence of the tooth and in that area where it will be most effective in deadening pain as promptly as possible. y

An injection needle of the type in question is of small outside diameter, in the order of about 1%;4 inch, tubular throughout its length and sharpened at the end. Since the needle is hollow it is obvious that the point must be in the' wall. Accordingly, the end of the needle is ground in a diagonal manner with the point being on one side of the circumference and the opening at the end of the needle passage being in the form of an ellipse. A dentist in using such needle preferably inserts. it into thel patients gum so that the ellipticalopening faces the tooth and in this manner the drug when forced in will become effective quicker and more effectively than if the elliptical opening faced away from the tooth.

It is with a view toward overcoming the problem of rotating the syringe approximately 180 when treating teeth on opposite sides of the mouth and approximately 90 when treating the front teeth that this invention is directed. The necessity of having the elliptical opening at. the end of the needle facing the tooth to be treated, if best results are to be obtained, is well recognized. Accordingly, I have devised a mechanism in the form of an adapter and a special needle construction which will enable the dentist to quickly and readily position the needle with yrespect to the syringe so that the elliptical opening will face with certainty in the desired direction, considering the normal position in which the syringe is held by the dentist as he applies novocaine to particular teeth. l

In the preferred form of the'invention, I providefour f han stes Patent point of connection.

2 Y positions. However, the construction may provide for the positioning of the needle at other numbers of positions, as for example, three positions spaced 120 apart or ve positions in which the needle may be set at any of ve positions spaced 72 apart. In the ordinary case, however, considering the-dexterity of .the dentist and the location of teeth about the jaw, lit has been fou-nd that four needle positions, each apart, are adequate to meet the needs of the average practitioner. j

From .the foregoing explanation it will be seen that the invention contemplates a needle construction which includes as part thereof a specially designed hub suit- 'ably marked so that lby examination of the hub the direction in which the elliptical `opening at the end of the needle faces Iwith respect to the adapter that holds the needle and to the body of the syringe will Xbe 'known to the user. The invention further contemplates a novel adapter designed to secure the needle to the yend of the syringe in fluid ltight relationship so that the novocaine maybe forced into the needle without leakage at the When the adapter,`which is in screw threaded relation with the syringe tbody, is screwed up tight, it'will assume a constant position with respect to the finger-gripping elements associated with the syringe body. Thus, the dentist by an examination of the markings on the hub that is lxed with respect to the needle' will always know the angular position of the elliptical needle opening with respect Ito the adapter and syringe body and with this knowledge maymore efliciently utilize the instrument in applying novocaine or other drug to:

the patients gum.

The invention will be more clearly understood as the description proceeds with the aid of the accompanying drawings, in which Fig. 1 is a side elevation of a typical syringe body,

having aixed thereto an injection needle held ina bent position. by the needle guard with the elliptical openingy at the end of the needle being in first position.

Fig. 2 is a View of the upper part of Fig'. 1 in which the needle has been rotated 90"` to second position with the elliptical opening correspondingly shifted.

Fig. 3 is aview similar to Fig. 2 in which the needle has been rotated another 90'to third position.

Fig. 4 is a view similar to Figs. 2 and 3 in which the needle has been rotated an additional 90 to fourth.

position.

Fig.` 5 is an enlarged view similar to Figs. 1 to 4 and' partly in section on the line 5 5 of Fig. 10showing further details `of the needle hub and adapter construction, w1th the needle in secured operating position.

Fig. 6 is a view similar to Fig. 5 with the adapter par? Fig.. 9 illustrates a further modication in which the hub 1s designed to permit rotation to any one of fiver positions.

Fig. l0 is a side elevation looking from the right of any `of Figs. 1, 2, 3 or 4 toshowthe manner in which the adapter is cut away to permit the hub to be viewed so that" the position of the needle may be known to the user.

Referring to Fig. l, there is shown the overall organi-' zation of the complete syringe unit, which comprises a syringe body 2, al plunger 4, operable by means ofthe; handle end 6 to force the novocaine from a container" 3 positioned in the syringe body into the injection needle 8. The finger gripping elements enable the dentist to hold the syringe body in his hand while applying pressure to plunger 4. v

An adapter 12 is in screw threaded engagement with thethreaded male member 14 (see Figs. 5 and 6) of the syringe body 2 and serves as a holder and securing means forboth the needle 8 and the needle guard 16.

Referring more particularly to Figs. 5 and 6 the adapter 12 comprises an upper extension 18, having an axial bore 20, through which extends needle S. Secured to the needle in fixed relation is a hub 22', concentric therewith and, in the construction shown, square in crosssection at that portion numbered 2'4. The upper portion 26, has its corners charnfered at 28 and the lower portion 30, has'its corners chamfered at 32. By so doing, the side ofthe hub 22 .presents the appearance of a cross and acts as a suitable setting for the numbers 1, 2, 3 and 4 shown in Figs. 1 to 4, which are applied in order to the four sides of the hub.

The interior bore of the adapter below bore is enlarged as at 34, to be square in cross section to receive the hub 22, in any one of the four angular posi-V rotated to be set `at any one of the four desired posi-- tions. In Fig. 6 the needle and hub are shown in the condition of being rotated from first position to fourth position.

As further shown in Fig. 5, the threaded male member 14, of syringe body 2, is in threaded engagement with the female threads 38 of the lower portion of the adapter body and the tapered seat 40, of member 14 presses tightly against the corresponding seat 42, on the lower end of hub extension 44, thus forcing the hub firmly upwardly into the square cavity 34.

With the hub and needle secured in the position shown in Fig. 5, the elliptical opening 46 at the end of needle 8 will be facing away as viewed in Fig. 4. When the hub is set in first position, as shown in Fig. l, the elliptical opening 46 will face to the left. When in second position, as shown in Fig. 2, the elliptical opening will face the viewer and in Fig. 3, with the hub in third position, the opening 46 will face to the right.

As shown in the drawings, the hub 22 is located relatively close to the admission end of the needle leaving a long and Very flexible portion on the discharge side. This long needle portion is supported intermediate the hub and the discharge end by an apertured needle guard 16. The needle guard is capable of directing the needle diagonally as shown because of the liexibility of the needle. In fact, the supporting needle guard is necessary because the needle is too long and flexible to be used properly without such support.

The .adapter 12 extends laterally of the syringe body and hasv a vertical hole therethrough in which is posi-- tioned needle guard 16, which may be held inY any selected Vertical position by the set screw 48. By shifting the position of needle -guard 16 with respect to adapter 12, the distance from the end of needle 8 to the button 50 may be varied. This construction is useful in controllingV or determining the distance to which the needle is to be inserted in the patients gum but constitutes no part of the present invention.

In further explanation of the operation ofthe invention, let us assume that the needle 8 has been aihxed in first position with respect tothe syringe body 2. and adapter 12, as shown in Fig. l. The dentistutilizing the instrument will appreciate thatV when-holding the syringe body inY his hand in normal operating position, the el-v liptical opening facing `to the left will be in a position that will make it easy for him to insert the needle against.

- the third position.

a particular tooth with the opening 46 facing the tooth. Accordingly, for such teeth he will use the instrument with needle in irst position. Having treated such tooth, it may then become necessary for him to treat a tooth on the other side of the same or another patients mouth, which, for best results, requires that the opening 46 face in the direction of that shown in Fig. 3, which is In such case, the dentist will then unscrew the syringe body from the adapter a few turns, bringing itto the position shown in Fig. 6. In this position, the hub 22 may then be pushed down to the position shown in Fig. 6 and may be rotated by twisting the needle with the fingers so that the needle and hub are turned to third position.` The threaded element 14 is then screwed back into the adapter, forcing the hub 22 up into the square cavity 34, thereby to secure the needle in third position. The dentist then knows that the elliptical opening 46 faces with respect to the adapter and syringe in a position opposite that of the irst position. The dentist is then able to use the instrument with assurance that when the needle is inserted alongside the appropriate tooth the novocaine will discharge from the needle in the direction of the tooth. This is of considerable advantage since it is recognized by dentists that in conducting these injection operations without the benefit of positive Vknowledge of the direction of the elliptical opening, mistakes are made in about 25% of the cases.

It will be understood vthat the needle guard 16 may or may not be used as desired. It has no influence on the direction assumed by the elliptical opening 46, which is under the sole control of the positioning of the hub 22 with respect to the corresponding cavity 34 in the adapter 12.

In view of the foregoing explanation, it will be understood that other modifications of my invention may be made but it is intended that :any such changes are to be within the scope of the appended claims.

I claim:

1. In a syringe, the combination of an injection needle and an adapter for holding said needle in any one of a. plurality of .angular positions with respect to said adapter, said needle having a diagonally disposed discharge end and having a polysided hub aflixed thereto, said adapter having a needle receiving bore and a polysided cavity to receive and hold said hub in any selected angular position with respect to said adapter, said adapter having an other cavity immediately adjacent and axially aligned with said polysided cavity of a size large enough to permit axial rotation of said hub when said hub has been moved thereto from said polysided cavity, whereby without removing said needle and hub from said adapter the position of said needle may be changed and the hub thereafter returned to non-rotatable position in said polysided cavity.

2. In a syringe, the combination of an injection needle and an adapter for holding said needle in any one of a plurality of angular positions with respect to said adapter,

' said needle having a diagonally disposed discharge end and having a polysided hub aixed thereto, said adapter having a needle receiving bore and a polysided cavity to receive and hold said hub in any selected angular position with respect to said adapter, the opposite ends of said hub being charnfered on Kall corners, thereby to produce a plurality of faces on said hub each of which `is in the form of a cross, each of said faces Vhaving thereon different identifying indicia, said adapter being cut away on one side of said polysided cavity whereby one face of said hub may be exposed to indicate the position of said needle discharge end, said adapter having another cavity also cutaway on one side and located immediately adjacent and axially aligned with said polysided cavity and of a size large enough to permit axial rotation of said hub when said hub has been moved thereto from said polysided cavity, whereby without removing said needle and hub from said adapter the position of said needle may be changed to another de sired position and the hub thereafter returned to nonrotatable position in said polysided cavity.

3. In combination, .a syringe body having a threaded tubular extension at one end, a cooperating adapter internally threaded at one end and having a needle receiving bore at its other end with an intermediate multisided cavity therebetween, an injection needle having a diagonally disposed discharge end land a cooperating multiside hub insertable into said adapter through the said one end only of said adapter whereby said hub may be seated in said cavity in non-rotatable relation and held therein by said extension when screwed into said adapter, indicia on the sides of said hub for indicating the angular position of said needle with respect to said adapter, said adapter having an opening through its side to permit viewing of at least one of said sides and the indicia thereon, said adapter having -a second cavity adjacent said mulltisided cavity into which said hub may be moved from said multisided cavity and manually rotated upon partial unscrewing of said extension from said adapter, thereby to shift the position of said needle discharge end with respect to said adapter.

4. A dental syringe comprising a threaded extension .associated with the syringe body and having a bore therethrough and a circular seat at the end thereof, an adapter for securing an injection needle to said syringe body in operative relationship thereto, said adapter comprising a tubular element internally threaded at one end section to receive the said threaded extension, a iirst cavity adjacent said threaded end section, a second cavity adjacent said iirst cavity of smaller cross sectional area than said rst cavity and of a polygonal cross-sectional form, and a smaller bore extending from said second cavity through the other end of said adapter, an injection needle having one end extending into the bore of said extension and the other end extending through the bore of said adapter, said needle being cut diagonally at its end to form a point at the adapter end thereof and providing an exit opening facing toward the side of said needle opposite said point, a hub secured to said needle, said hub having a plurality of indicia bearing faces and having on one end thereof a circular seat adapted to make a uid tight engagement with said extension seat, said hub, toward its other end, being of corresponding polygonal cross section to fit within said second cavity in non-rotatable relationship, said rst cavity being large enough in cross section so that when said hub is moved from second cavity to said lirst cavity, said hub and needle may be rotated about the needle axis to another position at which said hub may then be reseated in said second cavity to be again in nonrotatable relationship with said adapter, said threaded extension cooperating with the threads of said adapter to hold said hub in said `second cavity in fixed operative relationship, said adapter having an opening through its side to expose at least one of said indicia bearing faces whereby the user of the syringe may be advised of the direction in which said exit opening faces with respect to said adapter.

References Cited in the ille of this patent UNITED STATES PATENTS 1,274,081 Riethmueller July 30, 1918 1,520,508 Platt et al. Dec. 23, 1924 2,484,657 Son Oct. 11, 1949 2,545,115 Son Mar. 13, 1951 2,691,372 Lores Oct. 12, 1954 2,767,710 Blackman Oct. 23, 1956 FOREIGN PATENTS 127,586 Austria Apr. l1, 1932 

